CVE-2026-32661: Canon Marketing Japan Inc Guardianwall Mail Security Cloud Saas Version

Critical severity, CVSS 9.3. EPSS: 0.7% chance of exploitation in the next 30 days.

Stack-based buffer overflow vulnerability exists in GUARDIANWALL MailSuite and GUARDIANWALL Mail Security Cloud (SaaS version). If a remote attacker sends a specially crafted request to the product's web service, arbitrary code may be executed when the product is configured to run pop3wallpasswd with grdnwww user privilege.

Affected products

• Canon Marketing Japan Inc Guardianwall Mail Security Cloud Saas Version: version 2026 only
• Canon Marketing Japan Inc Guardianwall Mailsuite On-Premises Version

Published 2026-05-13. Last modified 2026-06-17.